Groovy Translation

not a question

OP solved the kata

you altered the return type of the method. it should return a List<Object>, not a List<Integer>. the input list can contain potentially any type, therefore so can the output, expect Strings

Where is my error ? :src/test/java/SolutionTests.java:43: error: incompatible types: List cannot be converted to List
List result = Kata.filterList(List.copyOf(input));
^
1 error

Agreed.

You have a typo in the example namely in the output of the last number:
ListFilterer.GetIntegersFromList(new List<object>(){1, 2, "a", "b", "aasf", "1", "123", 123}) => {1, 2, 231}

There should be:
ListFilterer.GetIntegersFromList(new List<object>(){1, 2, "a", "b", "aasf", "1", "123", 123}) => {1, 2, 123}

This kata is a subject to deduplication process here: https://github.com/codewars/content-issues/issues/227.
Please join the discussion to help us identify duplicate kata and retire them.

Posting a spoiler solution is not a kata issue, it's a user issue.

so easy, so fun!

Not a kata suggestion

More Optimal

the situation depends on the language. in C# and F# at least, the user's solution is required to return a list of int by the type signature, while e.g. Java returns a list of objects. there has likely been some translation drift over time, as this is a very old kata

Hi, I replied to your other comment. I see your logical point, though. Would you like to consider re-writing the description? You could leave that posted with a suggestion flag.